1. Field of the Invention
This invention relates to a method for producing characters and the like on the surface of an article, and more particularly to forming such characters in relief by chemical etching.
2. Description of the Prior Art
Chemical etching is a process known in the art as being useful in certain applications. Chemical etching has been utilized in the past to produce parts such as metal gaskets from very thin stock material. In this application, the etching process is used to totally remove the unwanted material. In other circumstances, chemical etching has been used to score material to make desired images therein, but the practice in the past has been to utilize the chemical etching only on the final article, and not on the mold or other pattern used to produce the article. Name plates, for example, have been chemically etched. The usual practice has been, however, to use a pantograph which manually gouges out the desired material. The known advantages of chemical etching include reducing tooling costs, production of a burr-free part which has not been stressed by the processing, wide application of the process to all metals and high tolerance levels.
Records, such as for phonographs or video tapes, have for a considerable time used the central portion of the usually circular disc to display proprietary and other information. The custom has been to print this information on a label which is applied to the record. This procedure contributes to the cost of records since the label entails printing, material and handling costs, and the application of the label must be performed in a separate production step. Another significant factor is the need to properly correlate the labels with the records upon which they are to be placed. The present invention has a particular application of providing this information on records by chemically etching the pattern from which the record is produced. Other procedures for physically working the pattern so that it will form the information on the produced record have not been found to be acceptable by the trade. The present invention, however, may be quickly, easily and inexpensively performed with excellent results being obtained.